Concrete With A Drinking Problem Could Reduce Flooding

Concrete – it’s all around you. You probably walk on it, drive on it, and maybe even sit on it! From a civil engineering standpoint, concrete really is a miracle material. But, it does have its downsides, especially in heavily developed urban areas. One of the most glaring of those downsides is the tendency for water to pool and flood on concrete. However, a new concrete formula could dramatically improve that by allowing water to drain quickly through the concrete itself.

While all unsealed concrete technically absorbs water, it does so very inefficiently and quickly becomes saturated. Once that happens, water will pool on the surface. This causes obvious problems for cars, as they become susceptible to hydroplaning. It also creates the potential for flooding in heavily paved areas.

This new concrete formula, called Topmix Permeable, is designed to reduce pooling by letting the water flow through at the rate of 600 liters per minute per square meter! It does this by using larger gravel pieces in the mix, which leaves bigger gaps for the water to drain down into. From there, it can be absorbed by the underlying soil, or routed safely away from roadways and parking lots.

Of course, this formula isn’t perfect. Its ability to pass through water also makes it likely to crack and quickly deteriorate in cold climates, as the water freezing and thawing inside the concrete will easily damage it. But, in warmer climates that receive a lot of rainfall in bursts, it could significantly improve safety.

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A Guy Named Bernoulli And Ducted Propeller Designs

Want to learn why ducted propellers improve both thrust and efficiency? Well, we’ve got both the lesson and the teacher for you. [Bruce Simpson] isn’t exactly a household name, but we bet most of you already know who he is. He’s the guy from New Zealand that in 2003 set out to make a $5000 DIY Cruise Missile – and he claims that he would have succeeded if the NZ Government hadn’t got in the way. Now-a-days [Bruce] focuses most of his energy on his two YouTube channels, RC Model Reviews and XJet.

Back to the lesson at hand: In the video after the break, he does a wonderful job explaining how the walls of a duct work to stop the high pressure area of the propeller from moving to the low pressure area. You’ll see something similar on the wings of jets aircraft. There will be a small vertical fin on the end of the wing, and much like a duct, it’s job is to physically separate the two areas and prevent tip vortex effects. That in turn increases efficiency. [Bruce] has some other great RC/model type videos, so if you like what you see, you might want to subscribe. Or you can learn more about the DIY Cruise Missile saga.

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Navigating The Oceans Is Deadly Without A Clock

I came across an interesting question this weekend: how do you establish your East/West location on the globe without modern technology? The answer depends on what you mean by “modern”, it turns out you only have to go back about three centuries to find there was no reliable way. The technology that changed that was a clock; a very special one that kept accurate time despite changing atmospheric conditions and motion. The invention of the Harrison H1 revolutionized maritime travel.

We can thank Andy Weir for getting me onto this topic. I just finished his amazing novel The Martian and I can confirm that George Graves’ opinion of the high quality of that novel is spot on. For the most part, Andy lines up challenges that Mark Watney faces and then engineers a solution around them. But when it came to plotting location on the surface of Mars he made just a passing reference to the need to have accurate clocks to determine longitude. I had always assumed that a sextant was all you needed. But unless you have a known landmark to sight from this will only establish your latitude (North/South position).

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Ethics In Engineering: Volkswagen’s Diesel Fiasco

Every so often – and usually not under the best of circumstance – the field of engineering as a whole is presented with a teaching moment. Volkswagen is currently embroiled in a huge scandal involving emissions testing of 11 Million diesel cars sold in recent years. It’s a problem that could cost VW dearly, to the tune of eighteen Billion dollars in the US alone, and will, without a doubt, end the careers of more than a few Volkswagen employees. In terms of automotive scandals, this is bigger than Unsafe at Any Speed. This is a bigger scandal than the Ford Pinto’s proclivity to explode. This is engineering history in the making, and an enormously teachable moment for ethics in engineering.

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Golf Cart Delorean

Quick Marty! We Have To Go Back, With The Golf Cart!

Talk about an awesome project. [Lucas Evanochko] was commissioned to build this totally rad Delorean style golf Cart for Red Deer College’s 30th annual Golf Tournament.

According to him, it’s been about 600 hours in the making – and they only started building it in July. This past week was its big unveiling, and it has had an overwhelmingly positive response so far!

They started with one of the club’s golf carts and modified it heavily, relying on the automotive expertise of [David Keykants] and [John Perrin] to turn it into the aw-worthy time machine it is today.  It has a 7” tablet built right into the dash to play music and use the Fluxy88 Time Circuits app. A big array of arcade buttons hooked up to an Adafruit Audio FX board play various sound bites from the movie, including the theme music!

All the accessories are powered off of a separate 12V system from the main 48V drive line. Oh and the Flux Capacitor? It’s controlled by a Trinket Pro. Check it out after the break. We love the detail that went into this!

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Dear TSA: This Is Why You Shouldn’t Post Pictures Of Your Keys Online

We have to hand it to the Transportation Security Administration (TSA). They seem to have a perfect track record of screwing up – and that’s not an easy thing to accomplish if you think about it. If it’s not reports of TSA agents stealing valuables or inappropriately groping passengers, there is the fun fact that in all the years since it was created in 2001, the agency hasn’t caught a single person seeking to do harm in the friendly skies. We’re actually okay with that if it means nobody is trying to do anything shady.

The most recent TSA folly seemed to practically fall into the Internet’s lap when a reporter for the The Washington Post published a hi-res picture of the entire set of TSA master keys while writing an article about how the TSA handles your bags after checking them at the counter. Well, the lock picking community when nuts and in a short time had 3D printed versions available and working. You can see it in action in the (twitter) video after the break.

For those that are not familiar with travel in the US, you are not allowed to use just any old lock on your bags. It has to be approved by the TSA – and that means that they have to be able to open it. So the TSA agents have a set of master keys that can open any bag if they need to look inside for some reason. If you put a non-TSA approved lock on the bag, that can make them a little angry, and you risk having your bag delayed or even cut open.

Of course, you can get into just about any suitcase with a ball point pen, so maybe this isn’t a real “security” issue, but it sure isn’t what you want to see from the agency that is supposed to protect you. Who knew that you could make keys from a photograph? We did way back in 2009 and way more in depth this May… maybe the TSA should start reading Hackaday?

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Thermal Vision HUD

Thermal Vision HUD Isn’t Only For Fighter-Jets!

In case you weren’t aware, thermal vision units have seen huge price reductions lately. There’s a few on the market for under $300! While that might still seem expensive, remember, it’s thermal-freaking-vision. [Tim] bought a Seek Thermal as soon as it was available, and just recently finished his first project with it — giving his car a thermal HUD for driving at night.

The Seek Thermal is a small thermal imaging unit that has a micro USB attachment for phones. Simply plug it in, and your phone becomes the preview window. But for mounting on your car, you can’t have it behind a window, because most glass is not transparent to heat wavelengths, so [Tim] had to get creative.

He designed and 3D printed a magnetic mount for it to sit on the hood of his car. But in the case any debris from the road hit it, he wanted to protect the lens. So he started looking up thermally transparent materials — turns out they’re really expensive.

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